Abstract:

In a pH 4.2~4.4 acidic medium, palladium(Ⅱ) reacted with moroxydine hydrochloride to form a cationic chelate [Pd(ABOB)2]2+, which reacted further with eosin Y(EY), erythrosin(Ery) or dibromofluorescein(DBF) to form ionassociation complexes, respectively. As a result, the resonance rayleigh scattering(RRS) intensities were enhanced greatly. The maximum RRS peak of three systems were located at 315 nm, RRS intensity was proportional to the concentration of moroxydine hydrochloride (ABOB) in a range of 0.012×10-6~1.2×10-6 g/mL (EY), 0.23×10-6~2.3×10-6 g/mL (Ery) or 0.24×10-6~1.5×10-6 g/mL (DBF), and the detection limit(3σ) was 0.003 6×10-6 g/mL (EY), 0.070×10-6 g/mL(Ery) or 0.025×10-6 g/mL (DBF), separately. The optimal conditions of the reaction and the properties of analytical chemistry were investigated. Therefore, a new method for the determination of ABOB by RRS was developed. The method has a high sensitivity and good selectivity, which has been applied to the determination of ABOB in serum and urine samples with satisfactory results. In addtion, the formation of the ion associaiation complexes, the reaction mechanism and the reasons of scattering enhanced has been discussed.

Key words: resonance Rayleigh scattering,moroxydine hydrochloride,palladium(Ⅱ),halide fluorescein dye